How do know if somebody likes you

like you

You can tell if someone likes you if they glance at you a lotand if they touch you

-if she uses every chance she has to talk to you or hang out with you
-if she smiles a lot at you
-if she giggles a lot
-if she initiates physical contact,ie hugs
-if she fidgets or plays with something when you're talking to her
-if she looks you in the eye when she's talking
-if she compliments you
-if she always tries to sit next to or near you
-if she often agrees with things you say
-if most of her body, especially her torso are pointed towards you when you're talking.
-if her feet are pointed toward you
-if she shows you her palm
-if she teases you, but in a playful way.
-if she looks a you a lot, especially when she thinks you're not looking.
-if she's super nice to you
-if she really tries to make you happy, even if it means going out of her way to do so.

If you think she's really into you so go out with her :)

well if they pick on you or talk about you in acute kind of way

wish I could help but I wanted to know the answer myself.